In recent years, a technique has been proposed which connects a home electrical apparatus with a network to control each apparatus by communicating through the network.
A power line communication (PLC) is noticed as such a technique for realizing a home network. The PLC is a method which superimposes a high frequency signal on a existing power line of 100 V (50/60 Hz), and bidirectionally communicates by using the power line as a transmission channel (for example, refer to Japanese Patent Application Laid-Open No. 2004-007497).
In the PLC, since an existing power incoming line and an existing power outlet can be utilized as they are, new wiring works are not required. In addition, in the PLC, since the communication can be executed only by inserting a plug to the outlet, the plug and play can be executed without a complex setting.
When connecting and controlling the home electrical apparatus with the network such as the PLC, each apparatus is required to cause a circuit for receiving a control signal from the network to constantly operate.
Thus, the standby power, which is consumed when the power is off, becomes large, as a result, the total electricity consumption becomes large. This is a problem.
Thus, a system has been proposed, which controls the power of an apparatus connected to the network, (for example, refer to Japanese Patent Application Laid-Open No. H02-202611). According to Japanese Patent Application Laid-Open No. H02-202611, a system is proposed, which controls the power supply to the apparatus on the network.
However, in the configuration of Japanese Patent Application Laid-Open No. H02-202611, regardless of a condition of the connected apparatus, the power supply to the connected apparatus is stopped.
Thus, a problem may be raised depending on the condition of the connected apparatus.
For example, in a case where the connected apparatus is a recorder which receives and records a television broadcast, if the power supply is stopped while recording, the recording is stopped halfway. This is a problem.